


Moonlit Fever

by SlytherinsDragon



Series: Holmescest ABO Works [2]
Category: Sherlock (TV)
Genre: Alpha Mycroft Holmes, Alpha/Beta/Omega Dynamics, First Time, M/M, Omega Sherlock, Teenlock, holmescest
Language: English
Status: Completed
Published: 2019-09-26
Updated: 2019-09-26
Packaged: 2020-10-28 21:01:25
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 1,162
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20785040
Author URL: https://archiveofourown.org/users/SlytherinsDragon/pseuds/SlytherinsDragon
Summary: It is summer. It is hot. In more ways than one.





	Moonlit Fever

**Author's Note:**

  * For [LadyGlinda](https://archiveofourown.org/users/LadyGlinda/gifts), [queenellis](https://archiveofourown.org/users/queenellis/gifts).

> This was supposed to be for the Promise series, but it kind of took a life of its own. So I will publish it as a separate entity.  
Funny how all these ABO stories always come to me when I am supposed to be asleep.

It is hot. Despite having the windows open – letting the barest of breezes into the room – beads of perspiration cling onto Mycroft’s skin as he twists and turns in his bed. This is only a singular dimension of the heat that plagues him. Mycroft – usually calm, collected and in control of every situation – is uncharacteristically restless; he feels feverish. His hand – of its own volition – finds its way to his cock. His fingers close around the shaft of his formidable organ – a standard deviation above the norm in terms of how Alphas are usually endowed – and he strokes.

He couldn’t possibly be in _rut_. Home for the summer from Oxford, there shouldn’t be any triggers. Blaming the lack of AC, he succumbs to fantasy. A deliciously hot, tight ring of muscle – clinging so achingly to the glans of his prick. A beautiful alabaster back – unmarked – undulating hypnotically on his shaft. A faceless and nameless omega. He sighs, letting his fingertip smear the precum from his slit.

A shadow catches his eye – and Mycroft feels the odd sensation that he is being watched. There is something in the air; an elusive scent in his nose – stimulating those primitive spots in his brain. Neurochemistry. For even he cannot defeat biology; the innate program that is writ in every cell in his body.

The moonlight spills into the corner of his room. And he sees it; he sees him. Tousled inky-black curls. An otherworldly sheen in his usually bright iridescent irises. The delicate structure of his face. It clicks. His brother – always seemingly so detached from the needs of the flesh – be it food, sleep and whatever else – is an omega. An omega going into heat.

His beautiful brother is going into heat. Mycroft’s hand stills, abruptly halting the languorous strokes of his cock. Ice floods his veins. His gorgeous, underaged brother is entering estrus. And this would be the first time. For everyone had thought Sherlock was a beta. He should shoo his brother from his perch in the corner; for if alpha and omega are kept in the same space for too long – the inevitable happens. It is elementary chemistry.

But his limbs feel heavy. The flesh is weak. Sherlock rises. Gracefully, his dressing gown slides off his torso and pools onto the floor. So lean. So young. So beautiful under the radiance of the moon. A living sculpture from the fabled artisans of antiquity. And those eyes – the orbs that seem to contain the entire galaxy – gaze upon him.

He sees a reflection of himself. The heat. The fever. The need. The desire.

His brother moves. Mycroft had always believed that the Alpha is the Dominant of the two sexes – from his old experience and societal beliefs – but Mycroft knows now that he has never been more wrong in his life. He is the prey, not the hunter. Sherlock – ever so carelessly elegant in his movements – stalks towards his bed. The predator. The panther in the shadows.

He should really end this. What would Mummy say?

But Sherlock springs up lightly onto his mattress. Confident. Hungry. And Mycroft can smell him – those damned delectable pheromones released by the scent glands. His eyes narrow – and Mycroft can almost hear Sherlock say: _“Don’t be ridiculous.”_

With what little strength remains in his limbs, Mycroft scoots backwards – fazed with the display of such overt sexuality. For the first time, Sherlock is the one that falters. Mycroft can read it in his brother’s slightly slouched posture: _“Don’t you want me, brother mine?”_

It feels like he had been kicked in the gut. This beautiful creature had chosen him. Him, out of all people, for this. His inner Alpha is dissatisfied. _Who is he to deny what Sherlock wants? Who is he to deny what they both want?_ Incest is a triviality. Hell is a manmade concept. Laws are made to be broken.

The spark returns to Sherlock’s eyes; Mycroft knows that Sherlock knows that he had won. Sherlock crawls forward – each motion calculated to show off the delights of his omega body. Not that Mycroft needs the advertisement. He had long been sold.

And he groans when real tight virginal heat engulfs the head of his cock; his brother sinks down slowly, ever so slowly down his prick. Sherlock undulates shallowly on his cock, seeming to be afraid of what would happen if he took the entire length in. Their eyes meet – and despite their differences – Mycroft knows that this is it for him. There would never be another omega for him.

Sherlock’s own omega cock – a beautiful, small, vestigial thing (functionally that is) – bobs along – leaking precum all over Mycroft’s abdomen. His brother’s eyes are now shut in bliss, little pants and noises denote his pleasure and Mycroft admires the contractions and relaxations of his beautiful musculature. He had always been jealous that Sherlock had inherited all the looks, but now he understands – for it would all be for him at the end – anyways.

If he doesn’t fuck this up, that is.

And, yes – he would rather look at his brother than himself during sex.

Mycroft needs more. But he resists the desire to thrust up. This is Sherlock’s first time. Better let him have this on his own terms, before Mycroft imposes his needs on him in the future. His brother’s breathing grows stilted, and Mycroft can feel his knot beginning to form at the base. His hands – again on instinct – reach for his brother's thighs and push him down further – causing him to take in more of his length. Sherlock whines. And Mycroft knows that the first time for an omega to take a knot – is not the most pleasant experience. It is agony. It is relief. The pleasure would soon follow. He thrusts upwards now – forcing his brother to take his entire length, wrenching noises from Sherlock that he hopes would not be heard by the other occupants of the house.

Sherlock throws back his neck without abandon in a wordless scream when the knot finally takes. Mycroft cums, pulsing his ejaculate into his brother’s cloaca in many voluminous spurts. In the light of the moon, his brother is gasping – his sweat-drenched hair clinging to his forehead. Mycroft carefully – after a minute to recover – rearranges them so that they are both lying in the bed. Sentiment between them has always been difficult to express – especially once Sherlock had hit adolescence. Instead of saying what he wants to say, he rests his palm on his brother’s chest. Sherlock closes his eyes as if to go to sleep – but Mycroft knows that the heat will soon crest again.

As dawn breaks, when the heat is finally over – Mycroft is surprised when Sherlock does not vacate the bed immediately. With the satisfaction of both _rut_ and _estrus_, it no longer feels so bloody hot – and Sherlock flings his arms around Mycroft – acknowledging that this is how things will be and will always be between them.


End file.
